The present invention relates to a poke-through floor fitting to enable electrical wires to safely pass through a floor. More specifically, the present invention relates to a fire-rated poke-through floor fitting having numerous telecommunications wires extending therethrough and intumescent material that resists the transfer of heat, smoke and flame through the fitting in case of fire.
Typically, fire-rated poke-through fittings provide a floor receptacle for electrical power outlets and/or for telecommunication jacks. Generally, these poke-through fittings are mounted in a core-drilled, approximately three or four inch diameter hole, which is commonly formed in a concrete floor.
Prior art fittings can prove hazardous if heat is easily transmitted through the fitting, either by the conductors or through the fitting itself, thus permitting heat from a fire to be transmitted through floors of a building. This problem has become more difficult in the last several years as additional conductors, for power and communications including voice and data, are used in poke-through fittings. The cross sectional area of a fitting may only be comprised of a predetermined amount of electrical wire, typically the electrical wire may only represent about 40 percent of the total cross sectional area of the fitting. Therefore, the more electrical wires passed through a fitting, the wider the fitting must be, and the wider the fitting, the more volume or cross-sectional area there is in the fitting through which heat can to be transmitted. Conventional fittings have reduced the diameter of the fitting to reduce the amount of heat, smoke and flame capable of passing through the fitting; however, this also reduces the number and/or volume of wires that can pass therethrough.
Since it is advantageous to increase the number of electrically and thermally conductive wires used in these fittings and still maintain a three or four inch aperture in the floor, so that a minimal number of holes or passageways are made therein, the size of the conduit must increase. Increasing the diameter of the conduit, as stated above, increases the heat passable therethrough. Therefore, there is an ongoing need to develop an apparatus having a conduit that is as large as possible, while still resisting heat, smoke, and flame from passing therethrough.
Examples of prior art fittings are disclosed in the following U.S. Pat. Nos.: 4,770,643 and 5,763,826 to Castellani et al.; 5,032,690 to Bloom; 5,058,341 to Harbeke, Jr.; and 5,970,670 to Hoffman, the disclosures of which are hereby incorporated by reference.
Accordingly, an object of this invention is to provide an improved fire-rated poke-through floor fitting.
Another object of this invention is to provide a floor fitting capable of limiting the transfer of heat, smoke and flame from a fire therethrough, while still allowing numerous electrical wires to pass therethrough.
Yet another object of this invention is provide a floor fitting about the same size as the aperture in the floor and still prevent heat, smoke and flame from a fire from passing therethrough.
The foregoing objects are basically obtained by providing a fitting for extending through an aperture in a floor, comprising a conduit having a first surface and a second surface, at least one passageway extending from said first surface to said second surface, at least one electrical wire passing through the conduit and intumescent material located adjacent the inside of the at least one passageway, the intumescent material expanding inwardly through the at least one passageway when exposed to a predetermined amount of heat.